Don't Miss

No Power In LCD Monitor

By on September 4, 2008


Whenever you switch “On” LCD Monitor and the Power LED indicator doesn’t lit don’t always assume it was the power supply problem. You must understand that the source of voltage to the power LED indicator was from the Mainboard particularly from the MCU. If the MCU have problem or the internal DATA had been corrupted then it won’t be able to send an “On” signal to the LED. This problem happened many times in the ACER and the BenQ LCD Monitor and replacement of the Main board solved the problem.

In order to isolate whether is the Mainboard or the power supply problem, you just need to measure the output voltages from the power supply. If you got all the voltages to the main board and the LED does not light then suspect a faulty Main board. If there is no voltages at all then suspect the power supply fault. Be remind that i had came across before the Power On/Off micro switch button failure and with a new replacement brought back the display-of course the LED lit! You can easily test the On/Off button using an ohmmeter or even with the help of continuity check.



  1. nowdaygood

    September 4, 2008 at 9:15 pm

    Dear Jestine
    I learn to you a lot.
    thank you very much.
    I repairing LCD SamSung 17' , the display all white color, not see any picture on it.
    Can you tell me how to troubleshoot this problem ?
    By the way How are you to day ?

  2. admin

    September 4, 2008 at 10:52 pm

    You are welcome and I'm fine today. As for the white display try check the supply voltage to the lcd controller board. If no voltage to the lcd controller board, the display will turn white.


  3. mohd firdaus

    November 3, 2008 at 12:17 pm

    my lcd monitor,have a problem..when i switch on the lcd monitor,the lcd could not 'ON',because at the secondry at the transformer NO output,but have the input from primary transformer..i hope you can help me very fast...urgent!!!tq..muah!

  4. admin

    November 3, 2008 at 10:20 pm

    Hi Mohd,
    Have you check all the components in the primary side? Many times a shorted secondary output diode could a dead power supply too. make sure the power ic have supply voltage in.



Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.